Asthma

What is asthma?

Asthma is a chronic, inflammatory lung disease involving recurrent breathing problems. The characteristics of asthma are three airway problems:

Obstruction

Inflammation

Hyperresponsiveness

What are the symptoms of asthma?

Common symptoms of asthma are listed below. However, each individual may experience symptoms differently.

In some cases, the only symptom is a chronic cough, especially at night, or tightness, coughing, noisy breathing, or wheezing. Some people think they have recurrent bronchitis, since respiratory infections usually settle in the chest in a person predisposed to asthma.

Asthma may resemble other respiratory problems such as emphysema, bronchitis, and lower respiratory infections. Many people with asthma do not know they have it. Consult your doctor for a diagnosis.

What causes asthma?

The basic cause of the lung abnormality in asthma is not yet known, although health care professionals have established that it is a special type of inflammation of the airway that leads to the following:

Contraction of airway muscles

Mucus production

Swelling in the airways

It is important to know that asthma is not caused by emotional factors—as commonly believed years ago. Emotional anxiety and nervous stress can cause fatigue, which may affect the immune system and increase asthma symptoms, or aggravate an attack. However, these reactions are considered to be more of an effect than a cause.

What happens during an asthma attack?

People with asthma have acute episodes when the air passages in their lungs get narrower, and breathing becomes more difficult. These problems are caused by an oversensitivity of the lungs and airways:

Lungs and airways overreact to certain triggers and become inflamed and clogged.

Breathing becomes harder and may hurt.

There may be coughing.

There may be a wheezing or whistling sound, which is typical of asthma. Wheezing occurs because:

Muscles that surround the airways tighten, and the inner lining of the airways swells and pushes inward.

Membranes that line the airways secrete extra mucus.

The mucus can form plugs that further block the air passages.

The rush of air through the narrowed airways produces the wheezing sounds.

What are the risk factors for an asthma attack?

Although anyone may have an asthma attack, it most commonly occurs in:

Children and adolescents between age 5 and 17

Females

People living in urban communities

Other factors include:

Family history of asthma

Personal medical history of allergies

How is asthma diagnosed?

To diagnose asthma and distinguish it from other lung disorders, doctors rely on a combination of medical history, physical examination, and laboratory tests, which may include:

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Spirometry. A spirometer is a device used by your doctor that assesses lung function. Spirometry is the evaluation of lung function with a spirometer. The test is performed by blowing as hard as possible into a tube connected to a small machine (a spirometer) that measures the amount of air breathed out and in as well as the speed it is breathed out. This is one of the simplest, most common pulmonary function tests and may be necessary for any/all of the following reasons:

To determine how well the lungs receive, hold, and utilize air

To monitor a lung disease

To monitor the effectiveness of treatment

To determine the severity of a lung disease

To determine whether the lung disease is restrictive (decreased airflow) or obstructive (disruption of airflow)

Peak flow monitoring (PFM). A device is used to measure the fastest speed in which a person can blow air out of the lungs. To use a peak flow meter, a person takes a deep breath in and then blows as hard and fast as possible into a mouthpiece. During an asthma or other respiratory flare-up, the large airways in the lungs slowly begin to narrow. This will slow the speed of air leaving the lungs and can be measured by a PFM. This measurement is very important in evaluating how well or how poorly the disease is being controlled.